1. Field of the Invention
The present invention relates to a module incorporating electronic component, and more particularly to a module incorporating electronic component including a structure that covers an electronic component bonded onto a substrate with a sealing resin.
2. Description of the Related Art
Recently, a module incorporating electronic component in which a plurality of electronic components are bonded onto a substrate at high density has been widely spread. The module incorporating electronic component is variously developed such that the bonded electronic components are covered with a metal case, or the bonded electronic components are covered with a sealing resin. Especially, in the case where the bonded electronic components are covered with the sealing resin, when bonding strength between the sealing resin and the substrate is increased, reliability of the module incorporating electronic component can be improved. Here, in a case where a wiring pattern and the electronic component are provided on the substrate, the bonding strength between the sealing resin and the substrate can be determined by combining adhesion strength between the sealing resin and the substrate, adhesion strength between the sealing resin and the wiring pattern, and adhesion strength between the sealing resin and the electronic component.
Japanese Unexamined Patent Publication No. 2005-183430 discloses a module incorporating electronic component in which a bonding strength between a sealing resin and a substrate is increased. The module incorporating electronic component disclosed in Japanese Unexamined Patent Publication No. 2005-183430 has at least one electronic component, an electrode to bond the electronic component to a surface layer, and a solder resist, and includes a wiring substrate having one or more wiring layers, and an insulating resin (sealing resin) to cover the electronic component electrically bonded (connected) to the electrode on the wiring substrate with a solder. According to the module incorporating electronic component disclosed in the Japanese Unexamined Patent Publication No. 2005-183430, a limited portion or an entirety of the solder resist provided in an outer periphery of the wiring substrate is removed, and the wiring substrate from which the solder resist has been removed is directly bonded and adhered to the insulating resin (sealing resin). Since adhesion strength between the insulating resin (sealing resin) and the wiring substrate is higher than an adhesion strength between the insulating resin (sealing resin) and the solder resist, the bonding strength between the insulating resin (sealing resin) and the substrate is increased by enlarging the part from which the solder resist is removed.
According to the module incorporating electronic component disclosed in the Japanese Unexamined Patent Publication No. 2005-183430, since the solder resist is formed on one surface of the wiring substrate, except for the outer periphery of the wiring substrate from which a limited portion or an entirety of the solder resist has been removed, an interface between the insulating resin (sealing resin) and the solder resist, and an interface between the solder resist and the wiring substrate exist over a wide range of the one surface of the wiring substrate. In general, it is known that a defect regarding the solder, for example, such as solder splash in which the solder is melted again due to heat in a soldering process and oozes between a fine gap, or a short circuit caused under the component, is generated at an interface between different kinds of materials.
Therefore, according to the module incorporating electronic component disclosed in the Japanese Unexamined Patent Publication No. 2005-183430, the interface between the insulating resin (sealing resin) and the solder resist, and the interface between the solder resist and the wiring substrate, exist over the wide range of the one surface of the wiring substrate as the interface between the different kinds of materials, so that the defect regarding the solder such as the solder splash could be generated there.